Muffler



- June 4, 1929. s; A, SNELL 1,715,630

MUFFLER Filed Feb. 26, 1926 dwg/WW2@ /QMBMLWM ATTORNEYS Patented 4, 1929.

" UNITED STATES PATENT OFFICE.

SAMUEL A. SNELL, 0F DETROIT, MICHIGAN, ASSIGNOR TO FREDERICK C. MATTHAEI,

` 0F DETROIT, MICHIGAN.

MUFFLEB.'

Application led February 26, 1926.' Serial No. 90,770.

rIhis invention relates to a muffler for use with motor cars, and has to do more particularly with a muffler so arranged and constructed that it may be used, when desired, to supply heated air for discharge into the body of the car.

Muiiiers which are employed to regulate the escape -of exhaust gases from an internal combustion engine to the atmosphere, so that a minimum of noise due to the rapidly recurring explosions is audible, perform their functions best when the gases are discharged from them at a pressure approximating atmospheric. Ordinarily, these mufflers comprise a succession of chambers in which the expansion of the hot compressed gases takes place, and the chambers are either arranged one within another, or else placed end to end within a casing, gases from the exhaust line entering the first chamber and flowing through the chambers successively to the discharge outlet from the last chamber. In the `first construction, in which the chambers are placed one within another, only the outside chamber can radiate heat to the atmosphere, while in the second construction, it is customary, in order to make the muffier compact, to form the chambers within a casing in such a manner that each chamber has but a small radiating surface. IVith either arrangement therefore, the gases are discharged from the muffler at a relatively high temperature, and but little reduction in pressure is secured due to the cooling of the gases within the muffler casing. These mufflers are therefore not as effective as they should be, and furthermore a considerable pressure is usually maintained within them, which places a back pressure on the motor and involves a loss of power.

In recent motor car development, closed vehicles now coming into widest use require some means for heating the interior of the car for winter use, and the heat contained in the exhaust gases from the motor is commonly utilized for the purpose, the gases being led through a heater connected to the exhaust line. In this heater the gases pass in heat 4I exchange relationship with air which flows through the heater and through a line dis-'- charging into the car body. These heaters' have heretofore taken the form of-a structure wholly distinct from the muiier, and the separate heaters and mufiiers have been connected successively in the exhaust line. The use of separate heaters and muiilers on the lcar involves considerable expense, both for the cost of material and for the installation of the devices.

The present invention is directed to the provision of an improved muflier so const'ructed and arranged that the exhaust gases drop in the temperature and pressure of the gases which results in an improved muiing effect. The novel muffler is further arranged so that air which passes through it for the purpose of reducing the temperature of the exhaust gases may be utilized for heating the car and the passages through which the air flows are so constructed and disposed within the muiHer as to offer but slight resistance to the fiow of exhaust. gases, and furthermore, air to'be heated is kept out of contact with the exhaust gases. In this new mufier heat is withdrawn from the gases, thus serving to lower the temperature and improve the muiing action and at the same time the heat is taken up by air which may, if desired, bev

led to the interior of the car. This single device, which is of simple construction4 and of low cost, consequently supplants the separate heaters and muiiiers heretofore employed, and its use affords a considerable saving in the costof materials and of installation.

The new muiiier consists of a casing within which is a lengthwise passage, connected at one end to the exhaust line from the motor. Surrounding this passage is a plurality of expansion chambers, together forming a cylinder, these chambersextending substantially throughout the length of the casing, and having their outer defining walls in contact with the atmosphere. The'chambers are shallow so that the gases flow therethrough in thin,

wide streams. From the end of the passage 'opposite to that through which the gases enter, is au opening leading to one of thc chambers and from the Opposite end of this chamber is an aperture leading into the chamber next adjacent. The chambers are all connected in this way, so that the gases flowing from the passage, traverse the casing a number of times, iiowing back and forth through the chambers successively. From the last chamber is an outlet to the atmosphere.

For the purpose of cooling the exhaust gases, a hollow walled tube is placed within the passage within the casing, and connections are. provided by which air is led into the space between the walls of the tube and one end thereof and withdrawn at the other. The tube is spaced from the walls of the passage so that the gases flow through and around' the tube, so that the air flowing lthrough the vtube in the form of a thin, an-

nular stream, rapidly absorbs heat from the gases, .owing to the large conduct-ing surfaces which separate the air and gases. The out-- let from this tube is connected to a line by which the heated air may be led to the interior of the car, and as a further improvement, the invention includes a control mechanism for use with the device by which the flow of heated air to the car may be regulated.

For a better understanding of the invention, reference will be made to the accompanying drawing, in which Fig. 1 is a view of a closed motor car illustrating the use of the improved .combined heater and muliler, 1 Fig. 2 is a vertical sectional view through the device, A

Figs. 3 and 4 are sectional views on the lines 3 3 and l-4 respectively,

Fig. 5 is a sectional view onthe line 5 5 of Fig. 4,

Fig. Gis an enlarged perspective view of a detail of the device, and

Fig. 7 is a plan view, partly in section,

' showing the improved control mechanisnn Referring now to the drawings, the closed motor car illustrated conventionally, is provided with the usual exhaust line l0, leading from the exhaust manifold of the motor. In

vthis line is disposed the muffler l1, through which the exhaust gases pass, these gases being discharged through a' line 12, extending to any convenient point at the rear of the vehicle and .discharging the gases to the atmosphere. Through the side walls of the casing are air inlet and out-let connections 13 and 14.

respectively, the outlet connection leading to a conduit 15, inwhich is a control device 16 beyond which the conduit leads to a register 17, disposed in the floor of the vehicle in the usual way. The air intake 13 may similarly be connected t' a conduit (not shown) extendig to any convenient point on the vehicle, through which air is admitted to the heating element within the device.

The interior structure of the device is illustrated in'F` ig. 2, 'and the device is seen to consist of a casing 18, preferably of cylindrical form, made of sheet metal stamped or casing may be made of two semi-cylindrical members, provided with contacting edge flanges seamed together and welded as shown at 18 or otherwise secured together. A plate 19 forms the end wall of the casing and in this plate is an opening20, provided with flangesin which may be received the end of thel exhaust line 10. A similar plate 2l is disposed at the other end of the casing, and both plates are preferably of a general cup shape having peripheral flanges 22 which lie in contact with the inner walls of the casingA and are welded or otherwise secured thereto along their edges, as at 23. The rear plate 21 has a central flanged opening 24, in which may be inserted the end of a pipe 12 forming the discharge line. The opening 20 forms an inlet for the exhaust gases and the opening 24 an outlet.

Within the casing is a partition 25, extending lengthwise thereof and defining a passage 26. This partition is made of sheet metal, preferably of cylindrical form, and is conveniently constructed of four arcuate plate members 27, having radial flanges 28 along their lateral edges. Four of t ese members are placed together to complete the cylinder, their edge lflanges lying in contact, and the flanges are then secured together by Welding, or in any other convenient manner. The end plate 19 has a cup-shaped depression 29,

Vat its center, forming a circular shoulder 30,

over which the partit-ion formed of the plate members is slipped. This shoulder supports the end of the partition securely within the casing. Within the casing, adjacent the end plate 21 is a somewhat similar plate 3,1, having a peripheral flange 32 which liesin contact with the inner wall of the'casing 18.

This plate 31 has a central depressionr33,

providing a shoulder 34, similar to the shoulder 30, the partition slipping over the shoulder and being supported thereby with reference to the casing wall.

The flanges 28 on the plate members divide the space between the partition 25 and the casing 18 into a plurality of expansion chambers, of which there are four in the device illustrated. These chambers lie side by side and extend substantially the length of the device. the casing is relatively small, andthe chambers are quite wide so that the gases, in their How through. the chambers, as will be described, take the for'm of thin Streams and give up heat rapidly through the outer casing wall, by reason of the large extent of the is)urface of this wall which defines each cham- The distance between the partition and The gases iowing from the exhaust line 10 direct contact with the columnar stream of air flowing through the space 55 and the annular stream flowing through the space 56. Thus the air is effectively raised in temperature and similarly the gases entering the first expansion chamber from the exhaust line, are rapidl'y lowered in temperature, and accordingly in pressure.

The air inlet 13 connected to the tube 53 in any convenient manner, leads air into the space between the double walls of tube 47, the air flowing through this space and being discharged through the pipe 54 and the air outlet 14. The air, heated by its passage through the heating device, flows through the conduit 14 to the register within the car, and in this conduit is a control mechanism comprising a chamber 57, made of metal in any convenient manner. The chamber has an opening 58, through which the air from the conduit 15 enters the chamber,` in the side. wall of the chamber is an opening 59, leading to the atmosphere, and in the end wall opposite the opening 5S is an opening 60 which is vconnected to a conduit 61 leading to the register 17 Vithin the chamber is pivotally mounted a damper platev 62, provided with a handle 63which extends through the floor of the car in any convenient position. A spring 64 secured to the damper plate acts to main-V tain it at either end of its travel about the pivot but prevents its being placed in anvintermediate position. This damper plate is arranged so that it may be swung either to close the opening 59 or the opening 60, arrd as illustrated in Fig. 7, the plate 62 closes the opening 59 so that the heated air from the conduit 15 passes through the chamber of the mechanism into the conduit 61 to the register 17. In the opposite position of the damper, as illustrated in dotted lines in Fig. 7, the air is diverted through the chamber and iiows out the opening 59 to the atmosphere. This permits regulation of the heatingl effect within the car body, and in summer weather, or when the temperature is comparatively high, the iiow of air into the car may be entirely shut off. At the same time air passes through the l air-heating chamber disposed within the passage 26, and thus acts to absorb heat from the gases within this first expansion chamber and assists in giving the desired muffiing effect, resulting from the' drop in pressure of the gases. l

The improved muier with the heater incorporated in it is of comparatively simple construction, and the several parts may-be made of metal stamped or otherwise shaped to proper form. The casing, the partition, and the air-heating chamber are all made of sections which may be quickly secured together at low cost by welding, and the muiiier may be readily installed so as to form a section of the exhaust line in the usual way. Since the heater and muer are' combined within asingle structure, the weight of the device is considerably less than that of a separate heater arid muier, and the cost is much less than that of the two devices separately produced. The new device gives a highly effective Inuf fling action, by reason of the succession of expansion chambers through which the gases iiow, and thisl muiiiing action is increased by reason of the drop in temperature of the gases flowing through the device. The heat given up bythe gases is utilized to heat air which' may be delivered to the car for heating 'the interior thereof when desired, the heater space, means for positivelyleading the gases along la tortuouspath between the opening and the outlet involving a seriesof successive passes of the gases from end toend of the casing, and an air chamber within the passage terminating short of the ends thereof and having an inlet and an voutlet passing through the casing wall between the ends thereof, the circulation of air through this" chamber acting to lower the temperature and pressure of the gases in the passage.

2. A muflier for use with an internal com- Y' bustion motor, which comprises the combination of a casing, a partition withinthe casing defining a passage spaced from the casing wall, an inlet for leading the exhaust gases from the motor into said passage, a plurality of expansion chambers in the space between the partition and the casing wall, an opening from the passage into one of the chambers,`

an outlet from another of the chambers, the chambers being connected through apertures so arranged .that the gases flow through the chambers successively and from end to end of the casing in passing from the opening to the outlet, and an air chamber within the passage between the ends thereof and having l an inlet .an-d an outlet passing through the wall of the casing, the circulation of air through this chamber serving to lower the temperature and the pressure of the gases in the passage.

3. A muiiler for use with an internal combustion motor which comprises the combination of a casing, a partition within the casing defining a passage spaced from the casing wall, an inlet for leading the exhaust gases from the motor into the passage, a plurality of expansion chambers arranged side, by side let passing through in the space between the partition and the caslng wall, an opening from the passage into one of the chambers, an outlet from another of the chambers, the chambers being connected through apertures so arranged that the gases flow through the chambers successively and from end to end of the casing 1n passing from the opening to the outlet, and an air chamber disposed within the passage and out of contact with the gases flowing through the expansion chambers, this air chamber having inlet and outlet connections ypermitting air to flow therethrough, whereby the air acts to lower the temperature and pressure of the gases in the passage.

4l. A muffler for use with an internal combustion motor which comprises the combination of a casing, a partition within the casing defining a passage spaced from the casing wall7 an inlet for leading the exhaust gases from the motor into the passage, a plurality of expansion chambers arranged side by side in the space between the partition and the casing wall, these chambers `extending substant-ially throughout the length of the casing, an opening Jfrom the passage into one of the chambers, an outlet from another of the chambers, the chambers being connected through apertures so arranged that the gases How through the chambers successively and from end to end of the casing in passing from the opening to the outlet, and an air chamber disposed within the passage between the ends thereof and having an inlet and an outlet passing through the side wall of the casing, the circulation of air through the chamber serving to lower the temperature and pressure of the gases in the passage.

5. A muffler for use'with an internal combustion motor which comprises the combination of a casing, a partition within the casing defining a passage spaced from the casing wall, an inlet Jfor leading the exhaust gases from the motor into the passage, a plurality of expansion chambers arranged in the space between the partition and the casing wall, adjacent chambers having a dening Wall in common, an opening from the passage into one of the chambers, an outlet from another of the chambers, the chambers being connected through apertures so arranged that the gases flow through the chambers successively and from end to end of the casing in passing from the opening to the outlet, and a double walled annular air chamber within the passag, terminating between the ends thereof and aving an inlet and an outthe casing wall, the circulation of air through the chamber acting to lower the temperature and pressure of the gasesin the passage.

6. A muiier for use with an internal comj bustion motor which comprises the combination of a casinga partition within the casing defining a passage spaced from the casing wall, an inlet for leading the exhaust gases from the motor into the passage, a plurality of expansion chambers arranged in the space between the partition and the casing wall, adjacent chambers having a common defining wall separating them, an opening from the passage into one of these chambers, an outlet from another of the chambers, apertures in the common defining walls through which adjacent chambers are in communication, these apertures being at opposite ends of adjacent chambers so that the gases flow through the chambers successively in passing from the opening to the outlet, and a double walled air chamber within the passage terminating short of the ends thereof and having inlet and outlet connections passing through the side wall of the casing, the circulation of air through the chamber Serving to lower the temperature. and pressure of the gases in the passage.

7 A muiiler for use with an internal combustion motor which comprises the combination of a casing, a partition within the casing defining a central passage, an inlet for leading exhaust gases from the motor into the passage, a series of expansion chambers arranged side by side and together enclosing the central passage, an opening from the passage into the first chamber in the series, connections between successive chambers arranged at opposite ends thereof, whereby the gases from the passage flow through the chambers successively in alternating directions and from end to end thereof, an outlet for the gases from the last chamber of the series, and a double walled tubular air cham- .ber within the passage terminating short of the ends thereol and having inlet and outlet connections passing through the side wall of the casing at a distance from the ends thereof, the circulation of air through the chamber acting to lower the temperature and pressure of the gases in the passage.

8. A muiiier for use with an internal combustion motor which comprises the combination of a cylindrical casing, a tubular partition lying within the chamber and defi-ning a passage lengthwise of the casing and spaced from the casing wall, an inlet for leading exhaust gases from the motor into the passage, means in the passage for lowering the temperature and pressure of the exhaust gases admitted thereto, a plurality of expansion chambers lying in the space between the casing and the partition, an opening from the passage into one'ot the chambers, a gas outlet from another of the chambers, apertures connecting the chambers and so arranged that the gas in flowing from the opening to the outlet traverses the chambers successively, and baiiie plates within the chambers adjacent the apertures for deiiecting the gas flow.

9, A muler for use with an internal comlbustion motor comprising the combination of a casing, a partition therein definingy a central passage spaced from the casing wall., a plurality of flangesv connecting'the partition and casing and forming expansion chambers, an inlet in the casing for leading exhaust gases into the passage, an opening leading lfrom thepassage at one end thereof into one tral passage extending lengthwise of the casing, a plurality of flanges connecting the partition and casing and forming a series of expansion chambers extending lengthwise of the casing and lying side by side, an inlet in the casing for leading exhaust gases into the passage, an opening leading from one end of the passage into one of the expansion chambers, an outlet for the gases from another of the chambers, apertures throughV which the chambers are in communication, these .apertures being arranged alternately at opposite ends of the chamber so that the gases in flowin from the opening to the outlet traverse the chambers consecutively, and baf- :lie plates within the chambers adjacent the apertures for deiecting the gas flow.

11. A mulller for use with an internal combustion motor comprising the combination of a cylindrical casing, a'central tubular partition having an open end and a closed end lying within the casing lengthwise thereof and defining a passage, a connectionbetween the exhaust line of the motor and the open end of the partition for leading exhaust gases into the passage, a plurality of lianges connecting the partition and casing and with theV latter defining a series of expansion chambers extending lengthwise of the casing, an opening near the closed end of the partition and leading from the passage into one of these chambers, an outlet for the gases from another of the chambers, apertures through which the chambers are in communication, these apertures being so arranged that the gases in flowing from the opening to the outlet traverse the chambers consecutively, and baille plates mounted on the flanges overlying the apertures and serving to deflect the flow of the gases therethrough.

l2; A muifler for use with an internal comy bustion motor and having a longitudinal central chamber into one end of which exhaust gases are admitted, a plurality of passages extending lengthwise of the muler to which the exhaust gases are admitted from said central chamber and through which they pass successively and from end to end of the casing to an outlet at the end of the mutHer opposite said inlet end, and an air chamber disposed within the passage and terminating short of the ends thereof andhaving inlet and outlet connections passing through the casing walls at a distance from the ends thereof, the circulation of air through the ychamber actin to lower the temperature of the gases in t e passage.

In testimony whereof I aiifix my signature.

SAMUEL A. SNELL. 

